Medical system and method of use

ABSTRACT

An instrument and method for applying thermal energy to targeted tissue. An instrument and method for tissue thermotherapy. In one embodiment, a method includes providing a vapor source comprising a pump configured for providing a flow of liquid media from a liquid media source into a vaporization chamber having a heating mechanism, actuating the pump to provide the liquid into the vaporization chamber, applying energy from the heating mechanism to convert a substantially water liquid media into a minimum water vapor level for causing an intended effect in tissue. For examples such levels can comprise at least 60% water vapor, at least 70% water vapor, at least 80% water vapor or at least 90% water vapor for causing an intended effect in tissue.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/918,962, filed Mar. 12, 2018, which is a division of U.S. applicationSer. No. 14/216,632, filed Mar. 17, 2014, which is a continuation ofU.S. application Ser. No. 13/946,885, filed Jul. 19, 2013, now U.S. Pat.No. 9,907,599, which is a continuation of U.S. application Ser. No.12/167,155, filed Jul. 2, 2008, now U.S. Pat. No. 8,579,892, whichclaims priority to U.S. Provisional Application No. 60/929,632 filedJul. 6, 2007. All of the above applications are incorporated herein bythis reference and made a part of this specification, together with thespecifications of all other commonly-invented applications cited in theabove applications.

FIELD OF THE INVENTION

This invention relates to medical instruments and systems for applyingenergy to tissue, and more particularly relates to a system forablating, sealing, welding, coagulating, shrinking or creating lesionsin tissue by means of contacting a targeted site in a patient with avapor phase media wherein a subsequent vapor-to-liquid phase change ofthe media applies thermal energy to the tissue to cause an intendedtherapeutic effect. Variations of the invention include devices andmethods for monitoring the vapor flow for various parameters with one ormore sensors. In yet additional variations, the invention includesdevices and methods for modulating parameters of the system in responseto the observed parameters.

BACKGROUND OF THE INVENTION

Various types of medical instruments utilizing radiofrequency (Rf)energy, laser energy, microwave energy and the like have been developedfor delivering thermal energy to tissue, for example to ablate tissue.While such prior art forms of energy delivery work well for someapplications, Rf, laser and microwave energy typically cannot causehighly “controlled” and “localized” thermal effects that are desirablein controlled ablation soft tissue for ablating a controlled depth orfor the creation of precise lesions in such tissue. In general, thenon-linear or non-uniform characteristics of tissue affectelectromagnetic energy distributions in tissue.

There remains a need for systems and methods that controllably applythermal energy in a controlled and localized manner without the lack ofcontrol often associated when Rf, laser and microwave energy are applieddirectly to tissue.

SUMMARY OF THE INVENTION

The present invention is adapted to provide improved methods ofcontrolled thermal energy delivery to localized tissue volumes, forexample for ablating, sealing, coagulating or otherwise damagingtargeted tissue, for example to ablate a lesion interstitially or toablate the lining of a body cavity. Of particular interest, the methodcauses thermal effects in targeted tissue without the use of Rf currentflow through the patient's body and without the potential of carbonizingtissue.

In general, the thermally-mediated treatment method comprises causing avapor-to-liquid phase state change in a selected media at a targetedtissue site thereby applying thermal energy substantially equal to theheat of vaporization of the selected media to the tissue site. Thethermally-mediated therapy can be delivered to tissue by suchvapor-to-liquid phase transitions, or “internal energy” releases, aboutthe working surfaces of several types of instruments for ablativetreatments of soft tissue. FIGS. 1A and 1B illustrate the phenomena ofphase transitional releases of internal energies. Such internal energyinvolves energy on the molecular and atomic scale—and in polyatomicgases is directly related to intermolecular attractive forces, as wellas rotational and vibrational kinetic energy. In other words, the methodof the invention exploits the phenomenon of internal energy transitionsbetween gaseous and liquid phases that involve very large amounts ofenergy compared to specific heat.

It has been found that the controlled application of such energy in acontrolled media-tissue interaction solves many of the vexing problemsassociated with energy-tissue interactions in Rf, laser and ultrasoundmodalities. The apparatus of the invention provides a vaporizationchamber in the interior of an instrument, in a source remote from theinstrument and/or in an instrument working end. A source provides liquidmedia to the interior vaporization chamber wherein energy is applied tocreate a selected volume of vapor media. In the process of theliquid-to-vapor phase transition of a liquid media, for example water,large amounts of energy are added to overcome the cohesive forcesbetween molecules in the liquid, and an additional amount of energy isrequired to expand the liquid 1000+ percent (PΔD) into a resulting vaporphase (see FIG. 1A). Conversely, in the vapor-to-liquid transition, suchenergy will be released at the phase transition at the interface withthe targeted tissue site. That is, the heat of vaporization is releasedat the interface when the media transitions from gaseous phase to liquidphase wherein the random, disordered motion of molecules in the vaporregain cohesion to convert to a liquid media. This release of energy(defined as the capacity for doing work) relating to intermolecularattractive forces is transformed into therapeutic heat for athermotherapy at the interface with the targeted body structure. Heatflow and work are both ways of transferring energy.

In FIG. 1A, the simplified visualization of internal energy is usefulfor understanding phase transition phenomena that involve internalenergy transitions between liquid and vapor phases. If heat were addedat a constant rate in FIG. 1A (graphically represented as 5 calories/gmblocks) to elevate the temperature of water through its phase change toa vapor phase, the additional energy required to achieve the phasechange (latent heat of vaporization) is represented by the large numberof 110+ blocks of energy at 100° C. in FIG. 1A. Still referring to FIG.1A, it can be easily understood that all other prior art ablationmodalities—Rf, laser, microwave and ultrasound—create energy densitiesby simply ramping up calories/gm as indicated by the temperature rangefrom 37° C. through 100° C. as in FIG. 1A. The prior art modalities makeno use of the phenomenon of phase transition energies as depicted inFIG. 1A.

FIG. 1B graphically represents a block diagram relating to energydelivery aspects of the present invention. The system provides forinsulative containment of an initial primary energy-media interactionwithin an interior vaporization chamber of medical thermotherapy system.The initial, ascendant energy-media interaction delivers energysufficient to achieve the heat of vaporization of a selected liquidmedia, such as water or saline solution, within an interior of thesystem. This aspect of the technology requires a highly controlledenergy source wherein a computer controller may need to modulated energyapplication between very large energy densities to initially surpass thelatent heat of vaporization with some energy sources (e.g. a resistiveheat source, an Rf energy source, a light energy source, a microwaveenergy source, an ultrasound source and/or an inductive heat source) andpotential subsequent lesser energy densities for maintaining a highvapor quality. Additionally, controller must control the pressure ofliquid flows for replenishing the selected liquid media at the requiredrate and optionally for controlling propagation velocity of the vaporphase media from the working end surface of the instrument. In use, themethod of the invention comprises the controlled application of energyto achieve the heat of vaporization as in FIG. 1A and the controlledvapor-to-liquid phase transition and vapor exit pressure to therebycontrol the interaction of a selected volume of vapor at the interfacewith tissue. The vapor-to-liquid phase transition can deposit 400, 500,600 or more cal/gram within the targeted tissue site to perform thethermal ablation with the vapor in typical pressures and temperatures.

In one variation, the present disclosure includes medical systems forapplying thermal energy to tissue, where the system comprises anelongated probe with an axis having an interior flow channel extendingto at least one outlet in a probe working end; a source of vapor mediaconfigured to provide a vapor flow through at least a portion of theinterior flow channel, wherein the vapor has a minimum temperature of;and at least one sensor in the flow channel for providing a signal of atleast one flow parameter selected from the group one of (i) existence ofa flow of the vapor media, (ii) quantification of a flow rate of thevapor media, and (iii) quality of the flow of the vapor media. Themedical system can include variations where the minimum temperaturevaries from at least 80° C., 100° C. 120° C., 140° C. and 160° C.However, other temperature ranges can be included depending upon thedesired application.

Sensors included in the above system include temperature sensor, animpedance sensor, a pressure sensor as well as an optical sensor.

In many variations, the devices and method described herein will includea visualization element placed within or adjacent to the treatment area.In many cases, the visualization element shall be coupled to a treatmentdevice (either by being placed within the device or otherwise attachedto the device. Any number of visualization elements can be incorporatedwith the methods and devices described herein. For example, avisualization element can include an optic fiber advanced within oradjacent to the device, a CCD camera affixed to the device or othervisualization means as commonly used in remote visualizationapplications. The visualization element can provide imaging before,during, and/or after the controlled flow egresses from the device. Inaddition, the visualization element can include thermal imagingcapabilities to monitor the vapor flow from the device or the treatmenteffect in tissue.

The source of vapor media can include a pressurized source of a liquidmedia and an energy source for phase conversion of the liquid media to avapor media. In addition, the medical system can further include acontroller capable of modulating a vapor parameter in response to asignal of a flow parameter; the vapor parameter selected from the groupof (i) flow rate of pressurized source of liquid media, (ii) inflowpressure of the pressurized source of liquid media, (iii) temperature ofthe liquid media, (iv) energy applied from the energy source to theliquid media, (v) flow rate of vapor media in the flow channel, (vi)pressure of the vapor media in the flow channel, (vi) temperature of thevapor media, and (vii) quality of vapor media.

In another variation, a novel medical system for applying thermal energyto tissue comprises an elongated probe with an axis having an interiorflow channel extending to at least one outlet in a probe working end,wherein a wall of the flow channel includes an insulative portion havinga thermal conductivity of less than a maximum thermal conductivity; anda source of vapor media configured to provide a vapor flow through atleast a portion of the interior flow channel, wherein the vapor has aminimum temperature

Variations of such systems include systems where the maximum thermalconductivity ranges from 0.05 W/mK, 0.01 W/mK and 0.005 W/mK.

Another variation of a novel medical system for delivering energy totissue comprises an elongated probe with a flow channel extending from aproximal portion of the probe to at least one flow outlet in anexpandable working end; a source of a vapor flow in communication withthe flow channel; and a recirculation channel having a distal endcommunicating with the working end.

The present disclosure also includes methods for applying energy tomammalian body structure, comprising providing an elongated probe with adistal working end and providing a pressure sensing mechanism formeasuring pressure within at least one of the probe and the bodystructure; providing a flow of a non-ionized flow media from at leastone port in the working end thereby applying energy to the bodystructure; and adjusting the pressure of the flow of the non-ionizedflow media from the at least one port in response to a measured changein pressure by the pressure sensing mechanism.

In an additional variation, the inventive methods include a method ofproviding a therapeutic effect in a mammalian subject comprisingproviding a vapor source comprising a pressure source configured forproviding a flow of liquid media from a liquid media source into avaporization chamber having a heating mechanism; actuating the pump toprovide the liquid into the vaporization chamber; applying energy fromthe heating mechanism to convert a substantially water media into aminimum water vapor; and introducing said vapor into an interface withtissue to cause the intended effect. While any range of water vapor canbe included within the scope of this invention, variations include aminimum water vapor can range from 60% water vapor, 70% water vapor, 80%water vapor and 90% water vapor.

One embodiment of the invention comprises a system and method fordelivering ablative energy to a body lumen or cavity, for example in anendometrial ablation procedure. One embodiment comprises an elongatedprobe with an insulated rigid or flexible shaft with a distal workingend and a source of a vapor media that can be ejected from at least oneoutlet in the working end. The introduction and condensation of thevapor media is utilized to apply a selected level of thermal energy toablate a surface portion of the body cavity. The method includesproviding a vapor media capable of releasing the heat of vaporization,in one example, for global endometrial ablation. The method includesintroducing the vapor media at a flow rate of ranging from 0.001 to 20ml/min, 0.010 to 10 ml/min, 0.050 to 5 ml/min., at an inflow pressureranging from 0.5 to 1000 psi, 5 to 500 psi, and 25 to 200 psi. Themethod includes applying the selected level of thermal energy over aninterval ranging from 0.1 to 600 seconds; 0.5 to 300 seconds, and 1 to180 seconds. Further, the application of energy may be pulsed as asuitable pulse rate. The system and method further include providing acontroller for controlling the pressure in a body cavity, such as auterine cavity.

The systems and probes of the invention are configured for controlledapplication of the heat of vaporization of a vapor-to liquid phasetransition in an interface with tissue for tissue ablation, tissuesealing, tissue welding, and causing an immune response. In general, theinstrument and method of the invention cause thermal ablations rapidly,efficiently and uniformly over a tissue interface.

The instrument and method of the invention generate vapor phase mediathat is controllable as to volume and ejection pressure to provide anot-to-exceed temperature level that prevents desiccation, eschar, smokeand tissue sticking.

The instrument and method of the invention cause an energy-tissueinteraction that is imageable with intra-operative ultrasound or MRI.

The instrument and method of the invention cause thermal effects intissue that do not rely applying an electrical field across the tissueto be treated.

Additional advantages of the invention will be apparent from thefollowing description, the accompanying drawings and the appendedclaims.

All patents, patent applications and publications mentioned in thisspecification are herein incorporated by reference to the same extent asif each individual publication or patent application was specificallyand individually indicated to be incorporated by reference.

In addition, it is intended that combinations of aspects of the systemsand methods described herein as well as the various embodimentsthemselves, where possible, are within the scope of this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a graphical depiction of the quantity of energy needed toachieve the heat of vaporization of water.

FIG. 1B is a diagram of phase change energy release that underlies asystem and method of the invention.

FIG. 2 is a schematic view of an exemplary medical system.

FIG. 3 is a block diagram of a control method of the invention.

FIG. 4A is an illustration of the working end of FIG. 2 being introducedinto soft tissue to treat a targeted tissue volume.

FIG. 4B is an illustration of the working end of FIG. 4A showing thepropagation of vapor media in tissue in a method of use in ablating atumor.

FIG. 5 is an illustration of a working end similar to FIGS. 4A-4B withvapor outlets comprising microporosities in a porous wall.

FIG. 6A is another system embodiment with a vapor generator comprising aresistive heating mechanism remote from the probe handle and theneedle-like working end.

FIG. 6B is an illustration of the working end of FIG. 6A treatingretinal tissue.

FIG. 7 is an illustration of the needle-like working end as in FIGS. 2and 4A with a sensor system.

FIG. 8 is an illustration of a working end including an expandablemember.

FIG. 9A is an illustration of an expandable working end being introducedinto soft tissue.

FIG. 9B is an illustration of the working end of FIG. 9A showing thepropagation of vapor media in tissue to ablate tumorous tissue.

FIG. 10A is an illustration of an expandable working end and sleevebeing introduced into soft tissue.

FIG. 10B is an illustration of the working end of FIG. 10A showing thepropagation of vapor media in tissue.

FIG. 11 is a cut-away view of an expandable working end with arecirculation flow channel.

FIG. 12A is an illustration of an expandable working end configured forpositioning in a uterine cavity for an endometrial ablation treatment.

FIG. 12B is a sectional view of the expandable working end of FIG. 12A.

FIG. 12C is a view of another non-expandable working end in anendometrial ablation treatment method.

FIG. 12D is a view of a cross-section of an insulative wall portion of avapor delivery probe.

FIG. 13A is an illustration of another expandable working end with asurface electrode arrangement.

FIG. 13B is a sectional view of the expandable working end of FIG. 13A.

FIG. 14A is an illustration of a working end with a recirculationchannel and valve for controlling vapor flows from the working end.

FIG. 14B is another view of the working end of FIG. 14A with therecirculation channel and valve in a different configuration.

FIG. 15A is a view of a vapor delivery probe including a cross-sectionalview of an insulative wall about a vapor delivery channel.

FIG. 15B is a view of another vapor delivery probe similar to FIG. 15Awith a cross-sectional view of a different type of insulative wall abouta vapor delivery channel.

FIG. 15C is a view of another vapor delivery probe similar to FIGS.15A-15B with a cross-sectional view of a different type of insulativewall.

FIG. 15D is a view of another vapor delivery probe similar to FIGS.15B-15C with a cross-sectional view of a different type of insulativewall.

FIG. 15E is a view of another vapor delivery probe similar to FIG. 15Dwith a mechanical valve system in a first position.

FIG. 15F is a view of the probe of FIG. 15E with the mechanical valvesystem in a second position.

FIG. 16 is another working end similar to that of FIG. 15C including anexpansion member.

FIG. 17A is another perspective view of the vapor generator system ofFIG. 15.

FIG. 17B is another perspective view of the vapor generator system ofFIG. 15.

FIG. 18A is perspective view of components of the vapor generator systemof FIGS. 17A-17B.

FIG. 18B is another perspective view of components of the vaporgenerator system of FIG. 17A-17B.

FIG. 19 is a block diagram of components of the vapor generator systemof FIGS. 17A-18B.

FIG. 20 is a schematic view of a flexible vapor conduit of the vaporgenerator system of FIG. 17A.

FIG. 21 is a sectional view of a vapor flow channel and surroundingstructure used with the vapor generator system of FIGS. 17A-18B

FIG. 22 is a cut-away view of a vapor canister and multiple heatingsystems of the vapor generator system of FIGS. 17A-18B.

DETAILED DESCRIPTION OF THE INVENTION

As used in the specification, “a” or “an” means one or more. As used inthe claim(s), when used in conjunction with the word “comprising”, thewords “a” or “an” mean one or more. As used herein, “another” means asleast a second or more. “Substantially” or “substantial” mean largelybut not entirely. For example, substantially may mean about 10% to about99.999, about 25% to about 99.999% or about 50% to about 99.999%.

Treatment Media Source, Energy Source, Controller

Referring to FIG. 2, a schematic view of medical system 100 of thepresent invention is shown that is adapted for treating a tissue target,wherein the treatment comprises an ablation or thermotherapy and thetissue target can comprise any mammalian soft tissue to be ablated,sealed, contracted, coagulated, damaged or treated to elicit an immuneresponse. The system 100 include an instrument or probe body 102 with aproximal handle end 104 and an extension portion 105 having a distal orworking end indicated at 110. In one embodiment depicted in FIG. 2, thehandle end 104 and extension portion 105 generally extend aboutlongitudinal axis 115. In the embodiment of FIG. 2, the extensionportion 105 is a substantially rigid tubular member with at least oneflow channel therein, but the scope of the invention encompassesextension portions 105 of any mean diameter and any axial length, rigidor flexible, suited for treating a particular tissue target. In oneembodiment, a rigid extension portion 105 can comprise a 20 Ga. to 40Ga. needle with a short length for thermal treatment of a patient'scornea or a somewhat longer length for treating a patient's retina. Inanother embodiment, an elongate extension portion 105 can comprise asingle needle or a plurality of needles having suitable lengths fortumor or lesion ablation in a liver, breast, gall bladder, bone and thelike. In another embodiment, an elongate extension portion 105 cancomprise a flexible catheter for introduction through a body lumen toaccess at tissue target, with a diameter ranging from about 1 to 10 mm.In another embodiment, the extension portion 105 or working end 110 canbe articulatable, deflectable or deformable. The probe handle end 104can be configured as a hand-held member, or can be configured forcoupling to a robotic surgical system. In another embodiment, theworking end 110 carries an openable and closeable structure forcapturing tissue between first and second tissue-engaging surfaces (notshown), which can comprise actuatable components such as one or moreclamps, jaws, loops, snares and the like. The proximal handle end 104 ofthe probe can carry various actuator mechanisms known in the art foractuating components of the system 100, and/or one or more footswitchescan be used for actuating components of the system.

As can be seen in FIG. 2, the system 100 further includes a source 120of a flowable liquid treatment media 121 that communicates with a flowchannel 124 extending through the probe body 102 to at least one outlet125 in the working end 110. The outlet 125 can be singular or multipleand have any suitable dimension and orientation as will be describedfurther below. The distal tip 130 of the probe can be sharp forpenetrating tissue, or can be blunt-tipped or open-ended with outlet125.

In one embodiment shown in FIG. 2, an RF energy source 140 isoperatively connected to a thermal energy source or emitter (e.g.,opposing polarity electrodes 144 a, 144 b) in interior chamber 145 inthe proximal handle end 104 of the probe for converting the liquidtreatment media 121 from a liquid phase media to a non-liquid vaporphase media 122 with a heat of vaporization in the range of 60° C. to200° C., or 80° C. to 120° C. A vaporization system using Rf energy andopposing polarity electrodes is disclosed in U.S. patent applicationSer. No. 11/329,381, now U.S. Pat. No. 8,444,636, which is incorporatedherein by reference. Another embodiment of vapor generation system isdescribed in detail below in the Section titled “REMOTE VAPOR GENERATIONUNIT AND CONTROL SYSTEMS”. In any system embodiment, for example in thesystem of FIG. 2, a controller 150 is provided that comprises a computercontrol system configured for controlling the operating parameters ofinflows of liquid treatment media source 120 and energy applied to theliquid media by an energy source to cause the liquid-to-vaporconversion. The vapor generation systems described herein canconsistently produce a high quality vapor having a temperature of atleast 80° C., 100° C. 120° C., 140° C. and 160° C.

As can be seen in FIG. 2, the medical system 100 can further include anegative pressure or aspiration source indicated at 155 that is in fluidcommunication with a flow channel in probe 102 and working end 110 foraspirating treatment vapor media 122, body fluids, ablation by-products,tissue debris and the like from a targeted treatment site, as will befurther described below. In FIG. 2, the controller 150 also is capableof modulating the operating parameters of the negative pressure source155 to extract vapor media 122 from the treatment site or from theinterior of the working end 110 by means of a recirculation channel tocontrol flows of vapor media 122 as will be described further below.

In another embodiment, still referring to FIG. 2, medical system 100further includes secondary media source 160 for providing an inflow of asecond media, for example a biocompatible gas such as CO₂. In onemethod, a second media that includes at least one of depressurized CO₂,N₂, O₂ or H₂O can be introduced and combined with the vapor media 122.This second media 162 is introduced into the flow of non-ionized vapormedia for lowering the mass average temperature of the combined flow fortreating tissue. In another embodiment, the medical system 100 includesa source 170 of a therapeutic or pharmacological agent or a sealantcomposition indicated at 172 for providing an additional treatmenteffect in the target tissue. In FIG. 2, the controller indicated at 150also is configured to modulate the operating parameters of source 160and 170 to control inflows of a secondary vapor 162 and therapeuticagents, sealants or other compositions indicated at 172.

In FIG. 2, it is further illustrated that a sensor system 175 is carriedwithin the probe 102 for monitoring a parameter of the vapor media 122to thereby provide a feedback signal FS to the controller 150 by meansof feedback circuitry to thereby allow the controller to modulate theoutput or operating parameters of treatment media source 120, energysource 140, negative pressure source 155, secondary media source 160 andtherapeutic agent source 170. The sensor system 175 is further describedbelow, and in one embodiment comprises a flow sensor to determine flowsor the lack of a vapor flow. In another embodiment, the sensor system175 includes a temperature sensor. In another embodiment, sensor system175 includes a pressure sensor. In another embodiment, the sensor system175 includes a sensor arrangement for determining the quality of thevapor media, e.g., in terms or vapor saturation or the like. The sensorsystems will be described in more detail below.

Now turning to FIGS. 2 and 3, the controller 150 is capable of alloperational parameters of system 100, including modulating theoperational parameters in response to preset values or in response tofeedback signals FS from sensor system(s) 175 within the system 100 andprobe working end 110. In one embodiment, as depicted in the blockdiagram of FIG. 3, the system 100 and controller 150 are capable ofproviding or modulating an operational parameter comprising a flow rateof liquid phase treatment media 122 from pressurized source 120, whereinthe flow rate is within a range from about 0.001 to 20 ml/min, 0.010 to10 ml/min or 0.050 to 5 ml/min. The system 100 and controller 150 arefurther capable of providing or modulating another operational parametercomprising the inflow pressure of liquid phase treatment media 121 in arange from 0.5 to 1000 psi, 5 to 500 psi, or 25 to 200 psi. The system100 and controller 150 are further capable of providing or modulatinganother operational parameter comprising a selected level of energycapable of converting the liquid phase media into a non-liquid,non-ionized gas phase media, wherein the energy level is within a rangeof about 5 to 2,500 watts; 10 to 1,000 watts or 25 to 500 watts. Thesystem 100 and controller 150 are capable of applying the selected levelof energy to provide the phase conversion in the treatment media over aninterval ranging from 0.1 second to 10 minutes; 0.5 seconds to 5minutes, and 1 second to 60 seconds. The system 100 and controller 150are further capable of controlling parameters of the vapor phase mediaincluding the flow rate of non-ionized vapor media proximate an outlet125, the pressure of non-ionized vapor media at the outlet, thetemperature or mass average temperature of the vapor media, and thequality of non-ionized vapor media as will be described further below.

FIGS. 4A and 4B illustrate a working end 110 of the system 100 of FIG. 2and a method of use. As can be seen in FIG. 4A, a working end 110 issingular and configured as a needle-like device for penetrating intoand/or through a targeted tissue T such as a tumor in a tissue volume176. The tumor can be benign or malignant tissue, for example, in apatient's breast, uterus, lung, liver, kidney, gall bladder, stomach,pancreas, colon, GI tract, bladder, prostate, bone, vertebra, eye, brainor other tissue. In one embodiment of the invention, the extensionportion 104 is made of a metal, for example, stainless steel.Alternatively or additionally, at least some portions of the extensionportion can be fabricated of a polymer material such as PEEK, PTFE,Nylon or polypropylene. Also optionally, one or more components of theextension portion are formed of coated metal, for example, a coatingwith Teflon® to reduce friction upon insertion and to prevent tissuesticking following use. In one embodiment at in FIG. 4A, the working end110 includes a plurality of outlets 125 that allow vapor media to beejected in all radial directions over a selected treatment length of theworking end.

In one embodiment, the outer diameter of extension portion 105 orworking end 110 is, for example, 0.2 mm, 0.5 mm, 1 mm, 2 mm, 5 mm or anintermediate, smaller or larger diameter. Optionally, the outlets cancomprise microporosities 177 in a porous material as illustrated in FIG.5 for diffusion and distribution of vapor media flows about the surfaceof the working end. In one such embodiment, such porosities provide agreater restriction to vapor media outflows than adjacent targetedtissue which can vary greatly in vapor permeability. In this case, suchmicroporosities insure that vapor media outflows will occursubstantially uniformly over the surface of the working end. Optionally,the wall thickness of the working end 110 is from 0.05 to 0.5 mm.Optionally, the wall thickness decreases or increases towards the distalsharp tip 130 (FIG. 5). In one embodiment, the dimensions andorientations of outlets 125 are selected to diffuse and/or direct vapormedia propagation into targeted tissue T and more particularly to directvapor media into all targeted tissue to cause extracellular vaporpropagation and thus convective heating of the target tissue asindicated in FIG. 4B. As shown in FIGS, 4A-4B, the shape of the outlets125 can vary, for example, round, ellipsoid, rectangular, radiallyand/or axially symmetric or asymmetric. As shown in FIG. 5, a sleeve 178can be advanced or retracted relative to the outlets 125 to provide aselected exposure of such outlets to provide vapor injection over aselected length of the working end 110. Optionally, the outlets can beoriented in various ways, for example so that vapor media 122 is ejectedperpendicular to a surface of working end 110, or ejected is at an anglerelative to the axis 115 or angled relative to a plane perpendicular tothe axis. Optionally, the outlets can be disposed on a selected side orwithin a selected axial portion of working end, wherein rotation oraxial movement of the working end will direct vapor propagation andenergy delivery in a selected direction. In another embodiment, theworking end 110 can be disposed in a secondary outer sleeve that hasapertures in a particular side thereof for angular/axial movement intargeted tissue for directing vapor flows into the tissue.

FIG. 4B illustrates the working end 110 of system 100 ejecting vapormedia from the working end under selected operating parameters, forexample a selected pressure, vapor temperature, vapor quantity, vaporquality and duration of flow. The duration of flow can be a selectedpre-set or the hyperechoic aspect of the vapor flow can be imaged bymeans of ultrasound to allow the termination of vapor flows byobservation of the vapor plume relative to targeted tissue T. Asdepicted schematically in FIG. 4B, the vapor can propagateextracellularly in soft tissue to provide intense convective heating asthe vapor collapses into water droplets which results in effectivetissue ablation and cell death. As further depicted in FIG. 4B, thetissue is treated to provide an effective treatment margin 179 around atargeted tumorous volume. The vapor delivery step is continuous or canbe repeated at a high repetition rate to cause a pulsed form ofconvective heating and thermal energy delivery to the targeted tissue.The repetition rate vapor flows can vary, for example with flowdurations intervals from 0.01 to 20 seconds and intermediate offintervals from 0.01 to 5 seconds or intermediate, larger or smallerintervals.

In an exemplary embodiment as shown in FIGS. 4A-4B, the extensionportion 105 can be a unitary member such as a needle. In anotherembodiment, the extension portion 105 or working end 110 can be adetachable flexible body or rigid body, for example of any type selectedby a user with outlet sizes and orientations for a particular procedurewith the working end attached by threads or Luer fitting to a moreproximal portion of probe 102.

FIG. 6A illustrates another similar medical system 100′ wherein thesource 120 of a flowable liquid treatment media communicates with anenergy source 180 comprising a resistive heating system that can be amodular unit and can be remote from the proximal handle end 104 of probebody 102, or the resistive can be within the handle portion or withinthe extension member 105, or a combination of locations. Thus in oneembodiment, the conversion of a liquid media 121 to a vapor media 122can be accomplished by a resistive heating system and the vapor mediacan flow through an insulated conduit 181 to communicate with flowchannel 124 and then exit the probe 102 at an outlet 125 in the workingend 110. The controller 150 again is operatively coupled to all thesystem sources, sensors and component to control all operationalparameters for treating a tissue target. As depicted in FIG. 6B, oneembodiment comprised a probe with extension member 105 that comprises aneedle member with a blunt or sharp tip for penetration through thesclera or cornea to treat retinal tissue 182, for example to ablate andcoagulate blood vessels 184 in a treatment of certain types of maculardegeneration. The method can be accompanied by a penetrating endoscopeor a slit lamp can be used to localize the treatment.

Sensor Systems For Flows, Temperature, Pressure, Quality

Referring to FIG. 7, one embodiment of sensor system 175 is shown thatis carried by working end 110 of the probe 102 depicted in FIG. 2 fordetermining a first vapor media flow parameter, which can consist ofdetermining whether the vapor flow is in an “on” or “off” operatingmode. The working end 110 of FIG. 7 comprises a sharp-tipped needlesuited for needle ablation of any neoplasia or tumor tissue, such as abenign or malignant tumor as described previously, but can also be anyother form of vapor delivery tool. The needle can be any suitable gaugeand in one embodiment has a plurality of vapor outlets 125. In a typicaltreatment of targeted tissue, it is important to provide a sensor andfeedback signal indicating whether there is a flow, or leakage, of vapormedia 122 following treatment or in advance of treatment when the systemis in “off” mode. Similarly, it is important to provide a feedbacksignal indicating a flow of vapor media 122 when the system is in “on”mode. In the embodiment of FIG. 7, the sensor comprises at least onethermocouple or other temperature sensor indicated at 185 a, 185 b and185 c that are coupled to leads (indicated schematically at 186 a, 186 band 186 c) for sending feedback signals to controller 150. Thetemperature sensor can be a singular component or can be plurality ofcomponents spaced apart over any selected portion of the probe andworking end. In one embodiment, a feedback signal of any selectedtemperature from any thermocouple in the range of the heat ofvaporization of treatment media 122 would indicate that flow of vapormedia, or the lack of such a signal would indicate the lack of a flow ofvapor media. The sensors can be spaced apart by at least 0.1 mm, 0.5 mm,1 mm, 5 mm, 10 mm and 50 mm. In other embodiments, multiple temperaturesensing event can be averaged over time, averaged between spaced apartsensors, the rate of change of temperatures can be measured and thelike. In one embodiment, the leads 186 a, 186 b and 186 c are carried inan insulative layer of wall 188 of the extension member 105. Theinsulative layer of wall 188 can include any suitable polymer or ceramicfor providing thermal insulation. In one embodiment, the exterior of theworking end also is also provided with a lubricious material such asTeflon® which further insures against any tissue sticking to the workingend 110.

Still referring to FIG. 7, a sensor system 175 can provide a differenttype of feedback signal FS to indicate a flow rate or vapor media basedon a plurality of temperature sensors spaced apart within flow channel124. In one embodiment, the controller 150 includes algorithms capableof receiving feedback signals FS from at least first and secondthermocouples (e.g., 185 a and 185 c) at very high data acquisitionspeeds and compare the difference in temperatures at the spaced apartlocations. The measured temperature difference, when further combinedwith the time interval following the initiation of vapor media flows,can be compared against a library to thereby indicate the flow rate.

Another embodiment of sensor system 175 in a similar working end 110 isdepicted in FIG. 8, wherein the sensor is configured for indicatingvapor quality—in this case based on a plurality of spaced apartelectrodes 190 a and 190 b coupled to controller 150 and an electricalsource (not shown). In this embodiment, a current flow is providedwithin a circuit to the spaced apart electrodes 190 a and 190 b andduring vapor flows within channel 124 the impedance will vary dependingon the vapor quality or saturation, which can be processed by algorithmsin controller 150 and can be compared to a library of impedance levels,flow rates and the like to thereby determine vapor quality. It isimportant to have a sensor to provide feedback of vapor quality whichdetermines how much energy is being carried by a vapor flow. The term“vapor quality” is herein used to describe the percentage of the flowthat is actually water vapor as opposed to water droplets that is notphase-changed. In another embodiment (not shown) an optical sensor canbe used to determine vapor quality wherein a light emitter and receivercan determine vapor quality based on transmissibility or reflectance ofa vapor flow.

FIG. 8 further depicts a pressure sensor 192 in the working end 110 forproviding a signal as to vapor pressure. In operation, the controllercan receive the feedback signals FS relating to temperature, pressureand vapor quality to thereby modulate all other operating parametersdescribed above to optimize flow parameters for a particular treatmentof a target tissue, as depicted in FIG. 1. In one embodiment, a MEMSpressure transducer is used, which are known in the art. In anotherembodiment, a MEMS accelerometer coupled to a slightly translatablecoating can be utilized to generate a signal of changes in flow rate, ora MEMS microphone can be used to compare against a library of acousticvibrations to generate a signal of flow rates.

FIGS. 9A and 9B illustrate another embodiment of vapor delivery tool andworking end 110 that is coupled to a vapor source and controller 150 asdescribed above (see FIG. 2). In this embodiment, the extension member105 is similar to that of FIGS. 4A and 4B but includes an expandableworking end indicated at 210. As can be seen in FIGS. 9A-9B, the workingend includes a region that is woven, knit or braided from wire-likemetal or polymer filaments 211 around a flow channel 124 that extendsthrough extension member 105 and wherein the inflow pressure of thevapor 122 is controlled to cause expansion of the woven filament workingend at the same time as diffusing the vapor flow from the plurality ofoutlets 125 can between the filaments 211 (FIG. 9B). The expansion ofthe working end is adapted to apply compression against the soft tissueand tumor T to thereby alter convective heating effects in such tissue.Such compression increases local tissue density and can make tissuedensity more uniform, for example, by collapsing vessel and lumens inthe targeted tissue which may otherwise cause a pathway for convectiveheat transfer to migrate non-uniformly.

FIGS. 10A and 10B illustrate another vapor delivery tool with anextension member 105 having a working end 110 that carries anon-complaint or compliant expandable structure 222 such as a balloonmade of any suitable temperature resistant polymer known in the art. Theballoon 222 can be sealed and coupled to the extension member 105 byadhesives or collars. In a method of use as shown in FIGS. 10A-10B, theexpandable working end 220 can be carried is a retractable sheath 224that is inserted into tissue (FIG. 10A) and then withdrawn to disposethe working end 110 in the targeted tissue. The balloon 222 has aninterior chamber 225 with a wall 226 that is microporous or hasplurality of outlets 125 therein as depicted in FIG. 10B. As can be seenin FIG. 10B, the inflow of vapor 122 from source 120 is modulated by acontroller 150 to expand the balloon 222. Thereafter, the vaporpropagates from the outlets 125 in the balloon wall to apply energy tothe tissue interfacing with the balloon wall.

FIG. 11 is a cutaway view of another vapor delivery tool or probe withextension member 105 and working end 110 that includes an expandablestructure 222 similar to that of FIGS. 10A-10B. The embodiment of FIG.11 includes a first flow channel 124 for carrying the vapor into theinterior chamber 225 of the expandable structure 222 and a secondrecirculating flow channel 228 in communication with negative pressuresource 155 for aspiration or extraction of a flow of media from theinterior chamber 225. This embodiment thus uses both a pressurizedinflow source 120 and the recirculation channel 228 coupled to negativepressure source 155 to allow the controller to precisely modulate flowfrom outlets 125 in the expandable structure 222. The embodiment of FIG.11 is shown for convenience with a substantially symmetrical balloon,but it should be appreciated that the balloon can be any symmetric,elongated, complex or asymmetric shape and can be configured fordeployment and expansion in soft tissue or can be configured fordeployment in a body cavity or lumen, such as a blood vessel, AVM, apatient's uterus, a nasal passageway or sinus, a gall bladder or otherhollow organ, the gastrointestinal tract or the respiratory tract. Theexpandable structure 222 or balloon can have multiple chambers withinternal constraining elements to allow the balloon to deployably expandto an asymmetric shape.

FIGS. 12A and 12B depict another system and working end 110 with anasymmetric shaped expandable structure 222 configured for deployment ina patient's uterus to apply energy for an endometrial ablationtreatment. It can be seen that expandable structure 222 is shaped tooccupy the cavity of a uterus and has a plurality of interior chamberportions 225 collectively in FIG. 12B separated by a vapor impermeableor permeable wall 242. The expandable structure 222 can have from 2 to100 or more such chambers and is shown in FIGS. 12A and 12B with threechamber portions 244 a, 244 b, 244 c. The balloon wall 226 has vaporoutlets 125 as described previously, and further includes therecirculation channel 228 and pressure control system as described inthe embodiment of FIG. 11. The expandable structure 222 of FIG. 12B isshown with a plurality of outlets 125 or porosities in the wall 226 ofthe balloon, and it should be appreciated that the outlets can vary indensity and dimension to permit greater and lesser vapor propagationthrough selected regions of the wall. For example, greater vapor flowscan be directed to thicker endometrial portions to increase the depth ofablation, and lesser vapor flows can be directed to thinner layers ofthe endometrium and toward the fallopian tubes.

FIG. 12C illustrates another probe embodiment for applying energy to abody cavity and more particularly to a uterine cavity 300 foraccomplishing an endometrial ablation treatment. This embodiment issimilar to that of FIGS. 4A-4B wherein the working end 110 is anon-expandable tubular member. FIG. 12C illustrates the endometrium 305that is targeted for ablation to treat menorrhagia. The endometrium 305is the uterine lining that is inward of the myometrium 306 andperimetrium 307. The embodiment of FIG. 12C has working end 110 that hasa soft or blunt distal tip 310 that is dimensioned for insertion throughcervix 312. The working end 110 can range from about 2 mm to 8 mm indiameter, and can have a vapor delivery lumen 124 that is substantiallysmall for vapor delivery to one or more outlets 125 with the outletsdistal of expandable balloon 315. The extension member 105 includes witha substantial insulative layer 320 (further described below) thatextends to the working end 110. In this embodiment, the extension member105 and working end 110 can be fabricated of a polymer material such asPEEK, PTFE, Nylon or polypropylene and a plurality of outlets 125 forvapor ejection can be provided in selected radial directions over aselected length of the working end 110. In another embodiment, theworking end 110 can have a single outlet 125. In one embodiment, theworking end 110 has an expansion member or balloon 315 positionedproximal to the vapor outlet(s) 125 to prevent proximal vapor flowsretrograde from the uterine cavity and to protect the cervix 312 fromhigh temperatures. The deployment of balloon 315 can further allow aselected pressure to be maintained in the cavity wherein another lumen228 (aspiration lumen) with port 321 in the working end is coupled tonegative pressure source 155 that includes a valve configured to controloutflows from the uterine cavity with the valve operatively connected tocontroller 150. In another embodiment, the working end 110 can includeany inflatable, actuatable or spring-like frame to distend the cavity inthe uterus, as well as expandable balloons or similar structures (notshown) for preventing vapor flow into the fallopian tubes 322. As can beunderstood from FIG. 12C, the endometrial ablation system can have allof the features, sensors and subsystems described elsewhere herein inthe various embodiments. In one method, the system and controller canutilize the controller 150 and valve connected to the aspiration lumen228 in the probe valve to provide a pressure in the uterus duringtreatment ranging between 0.1 psi and 50 psi, between 0.2 psi and 10psi, and between 0.5 psi and 5 psi. In the embodiment of FIG. 12C, theinflation lumen to expand the balloon 322 is not shown and can bemanually operated or can be operatively coupled to controller 150. Inanother method, the system allows controlled distension of a body cavitywith a gas or vapor media, such as a uterine cavity, in combination withthe vapor media applying a selected amount of ablative energy uniformlyabout the surface of the distended body cavity.

In another aspect of the invention, a vapor delivery system as describedabove can have an extension member 105 (FIGS. 4A-12C) with an insulativewall, as depicted in the cross-sectional view of FIG. 12D. In FIG. 12D,it can be seen that at least one flow channel 124 is within an interiorof the surrounding structure or wall 324 that includes a thermallyinsulative layer or region indicated at 320. In one embodiment, theextension member 105 has a thin inner layer 325 around the flow channel124 which is of a biocompatible fluid impermeable material such as apolymer (Teflon®) or a metal such as a stainless steel. A flexible vapordelivery extension member can include an electroless plating over apolymer base to provide biocompatible inner layer 325. Outward from theinner layer 325 is the insulating region or layer 320 that can compriseair channels, voids with a partial vacuum, a region that carries anaerogel or aerogel particles optionally under a partial vacuum, a regionthat carries hollow glass or ceramic microspheres, or a region with achannel or multiple channels that provide for a flow of air or a liquidabout the at least one flow channel 124. An extension member 105 thatincludes flow channels or recirculation channels can be coupled to anypositive and negative pressure sources known in the art to cause a flowof air, cooling fluids, cryogenic fluids and the like through suchchannels. The exterior 326 of the wall 324 can be any suitable layer ofa high temperature resistant polymer such as PEEK. Other materials usedin an extension member can comprise formulations or blends of polymersthat include, but are not limited to PTFE, polyethylene terephthalate(PET), or PEBAX. PTFE (polytetrafluoroethylene) is a fluoropolymer whichhas high thermal stability (up to 260° C.), is chemically inert, has avery low dielectric constant, a very low surface friction and isinherently flame retardant. A range of homo and co-fluoropolymers arecommercialized under such names as Teflon®, Tefzel®, Neoflon®, Polyflon®and Hyflon®. In one embodiment, the insulative layer 320, or inner layer325 and insulating layer 320 in combination, or the entire wall 324, canhave a thermal conductivity of less than 0.05 W/mK, less than 0.01 W/mKor less than 0.005 W/mK. In another aspect of the invention, the wall isconfigured at least partially with materials interfacing the channelthat have a heat capacity of less than 2000 J/kgK for reducingcondensation in the flow channel upon the initiation of vapor flowtherethrough.

FIGS. 13A-13B illustrate another system with expandable working endsimilar to that of FIGS. 12A-12B with an additional energy deliverysystem carried by the expandable structure 222. As can be seen in FIG.13A, the surface of expandable structure 222 carries at least oneelectrode arrangement operatively coupled to an electrical source suchas an Rf source 332A and Rf controller 332B. The energy delivery systemcan comprise a surface electrode on the expandable structure 222 thatcooperates with a ground pad, or as shown in the FIG. 13A, the systemcan carry spaces apart bi-polar electrodes that can comprise conductivecoatings on a non-complaint balloon. In one embodiment of FIG. 13A,opposing polarity (+) and (−) electrodes 333A and 333B are shown and areadapted to apply energy to tissue as well as vapor 122 that exits theoutlets 125. The current flows between the electrodes 333A and 333B areindicated by dashed lines in FIG. 13A, with such electrodes spaced apartis four quadrants around the structure. It should be appreciated thatsuch spaced apart bi-polar electrode pairs can number from 2 to 100 ormore about the surface of the structure. In one embodiment, hypertonicsaline is vaporized to provide the flow of vapor 122 and saline dropletswhich will enhance Rf energy delivery to the tissue. FIG. 13B shows across section of a portion of wall 226 of the expandable structure ofFIG. 13A wherein the interior chambers 225 (collectively) are channelsin a thin film structure wall with outlets indicated at 125. In oneembodiment, as in FIGS. 13A and 13B, the larger openings 334 permitvapor in the cavity extracted by a central aspiration or recirculationchannel 228 at the interior of the structure similar to that of FIG. 11.The illustration of FIG. 13B does not show the interior constrainingelements 242 as in FIG. 12B, but it should be understood that any numberof such elements are possible to provide an asymmetric-shaped structurewhen pressurized.

In a method of use in treating the interior of an organ, with referenceto FIGS. 12A, 12B and 12C, one method includes introducing the workingend of an elongated probe introduction into a uterine cavity, providinga flow of a vapor media derived from water or saline from at least oneoutlet 125 in the working end 110 wherein the flow media applies aselected level of thermal energy to ablate at least portions of theendometrium. As described above, the ablation method is accomplished byallowing the vapor to collapse or condense to thereby release the heatof vaporization to uniformly ablate surface layers of the endometrium.Stated another way, the method includes converting the flow media from afirst phase to a second phase thereby controllably applying thermalenergy to the endometrium. One method includes introducing the flowmedia at a flow rate of ranging from 0.001 to 20 ml/min, 0.010 to 10ml/min, 0.050 to 5 ml/min. One method includes introducing the flowmedia at an inflow pressure ranging from 0.5 to 1000 psi, 5 to 500 psi,and 25 to 200 psi. One method further includes applying the selectedlevel of thermal energy over an interval ranging from 0.1 to 600seconds; 0.5 to 300 seconds, and 1 to 180 seconds. Another method asdescribed above includes providing a flow of a second media forcombining with the vapor 122 to alter the average mass temperature ofthe combined vapor and second media.

In another aspect of the method of treating a uterus or the interior ofanother hollow organ, with reference to FIG. 12C, the system can be usedto control the pressure within the uterus or other organ with controller150 as described above. In one method, the controller 150 can controlpressure in the cavity by modulating the inflow pressure of the flowmedia 122. In a related method, the controller 150 can control pressureby providing an outflow passageway in the probe for reducing pressure inthe cavity. In an endometrial ablation procedure, the method includesproviding a pressure in the uterus ranging between 0.1 psi and 6 psi,between 0.2 psi and 4 psi, and between 0.5 psi and 2 psi. This methodincludes controlling pressure in the uterus to distend the uterus duringtreatment. These methods also can be used when distending the uteruswith an expandable working end.

Recirculation Channel, Flow Control, Insulative Subsystems

FIGS. 14A and 14B depict another vapor deliver probe 335 with extensionmember 105 that can include the sensor subsystems as in the probe ofFIG. 7 and additionally is configured with a second or recirculatingflow channel 340 in the probe and extension member 105 that extends backto vent recirculation flows and optionally communicates with a negativepressure source 155 as depicted in FIG. 2. In one embodiment, the secondchannel or recirculating channel 340 is configured for controlling vaporflows to the outlet 125, which for example can be a single outlet or aplurality of outlets as in any embodiment described previously. In FIG.14A, it can be seen that vapor media 122 generated by vapor generatingcomponents as described above and controller 150 to provide apressurized vapor flow that flows distally through channel 124 and thenreverses direction to flow in the proximally direction within channelregion 342 that transitions into the second or recirculating channel340. It can be understood that vapor media flows will continue in pathof channel 124 and recirculation channel 340 so long as flow resistanceis less through this pathway than through the small cross-section vaporoutlet 125. In this aspect of the invention, the collectivecross-section of the outlet(s) 125 is substantially less than thecross-section of the recirculating channel 340, for example, less than20% of the recirculating channel 340, less than 10% of the recirculatingchannel 340, or less than 5% of the recirculating channel 340. Thesystem includes means for closing the recirculating channel 340 to thusforce vapor media 122 through the at least one outlet 125 to provides a“passive valve” at the outlet 125 and a method of instantly turning on avapor flow from outlet 125 when operating a vapor generator in acontinuous mode. In FIGS. 14A and 14B, it can be seen that a manualswitch 348 in the handle portion 104 can operate valve 350 to block therecirculating channel 340 thus providing the passive valve thatcomprises the reduced cross-section outlet 125 at the working end. Thisform of passive valve is very useful in small diameter elongatedextension members 105 such as an elongate flexible catheter. The switchcan be in a proximal handle end 102 of the probe or optionally in anegative pressure source 155 coupled to recirculating channel 340 andcan be operated by controller 150. In FIG. 14A, it can be understoodthat negative pressure source 155 can be operated to assist inexhausting vapor media from the recirculating channel 340 to enhance therecirculating flows. While the embodiment of FIGS. 14A-14B illustratesparallel channels 124 and 340, the channels can be varied, for examplebeing concentric as described further below, or varied in cross sectionand/or length. The embodiment of FIGS. 14A-14B depict a blunt-tipworking end 110 that can be used when injecting vapor into a lumen orbody cavity such as a patient's respiratory tract, blood vessel, uterus,gastrointestinal tract and the like. It can be understood that asharp-tip needle can be coupled to the distal end of the extensionmember 105 of FIGS. 14A-14B so that the passive valve is close to aneedle that is configured to penetrate tissue for interstitial vapordelivery.

The embodiment of FIGS. 14A and 14B further illustrates a sensor systemwith temperature sensors 185 a-185 c as described above in theembodiment of FIG. 7. In addition, FIGS. 14A and 14B illustrate avisualization element 98 placed within a probe 335. In this variationthe visualization element 98 is located in a working end 110 of theprobe 335. However, the visualization element 98 can be located in anyregion of the device either by being placed within the device orotherwise attached to the device. Any number of visualization element 98can be incorporated with the methods and devices described herein. Forexample, a visualization element 98 can include an optic fiber advancedwithin or adjacent to the device, a CCD camera affixed to the device orother visualization means as commonly used in remote visualizationapplications. The visualization element 98 can provide imaging before,during, and/or after the controlled flow egresses from the device. Inaddition, the visualization element can include thermal imagingcapabilities to monitor the vapor flow from the device or the treatmenteffect in tissue.

FIG. 15A illustrates a vapor delivery tool or probe 400 that has a hubor handle portion 402 with extension portion 105 and working end 110that is configured with an insulated wall 324 about flow channel 124 asin the embodiment depicted in FIG. 12D. As can be understood from FIG.15A, a liquid media source 120 and vapor generator provides vapor 122and can be coupled to a flexible vapor delivery conduit 404 with aconnector 406 that is coupled to Luer-type fitting 407 of the handleportion 402 of the probe. In one embodiment, the insulative region 320of the wall comprises an aerogel 408 or an aerogel in a sealedinsulative region 320 that is under a partial vacuum. Silica aerogelsare a common form of aerogel having a very low thermal conductivityranging from 0.03 W/m·K to 0.004 W/m·K. Other forms of aerogels may beused such as a carbon aerogel, or a combination silica and carbonaerogel.

As can be seen in FIG. 15A, the probe 400 includes a temperature sensor410 in the end of flow channel 124 that corresponds to a part of asensor system coupled through electrical lead 410 and connector 412 tocontroller 150 as described in the text accompanying FIGS. 7-8. Further,one embodiment carnies another sensor or thermocouple indicated at 415proximate an exterior surface of the extension member 105 coupled bylead 416 to the controller. The additional thermocouple 415, or aplurality of such thermocouples, can be used to measure surfacetemperature of an extension member in the interior of a patient's body,for example an elongate flexible catheter in a body lumen, to insurethat a surface temperatures is not elevated above a point that causes anunwanted effect in tissue. The thermocouple 415 is coupled to controller150 to provide feedback signals to thus allow modulation of a duty cycleor other operating parameter of vapor delivery.

In one aspect of the invention, a method of practicing a thermotherapyprocedure includes positioning an insulative extension portion of aprobe 400 in a patient's body to provide an access to a targeted site,and delivering a high temperature condensable vapor through a flowchannel 124 in the probe 400 to provide an intended effect wherein aprobe wall is configured with an insulative portion having a thermalconductivity of less than 0.05 W/mK, less than 0.01 W/mK or less than0.005 W/mK to limit thermal transfer from a probe to tissue. In oneembodiment, the probe 400 has a flow channel 124 with at region aroundthe flow channel that is fabricated of a material having a heat capacityof less than 3000 J/kgK, less than 2500 J/kgK, of less than 2000 J/kgK,which can prevent condensation and thus improve vapor quality. In oneembodiment, a system with a flow channel 124 between the vapor source120 and the outlet 125 having the materials with flow channel wallsincluding the low heat capacity material can provide a water vaporquality at the outlet 125 of at least 70% vapor, at least 80% vapor andleast 90% vapor. Further, the method includes providing such vapor overa duty cycle ranging from 5 seconds to 5 minutes with less than 10%variation in said vapor quality. The quality of vapor is directlycorrelated to the amount of energy applied to tissue, so that it iscritical to know the quality—and hence stored energy—in the vapor media.In other embodiments, the extension member 105 can be rigid, flexible,deflectable, malleable or curved. It can be understood that an elongateflexible catheter can be used in a treatment of varicose veins or otherendovascular treatments. The extension member 105 can have a length ofat least 10 mm, 25 mm, 50 mm and 100 mm. As can be seen in FIG. 15A, theextension member 105 can have markings indicated at 418 for monitoringdepth in skin, and the markings also can be radiopaque markings.

A probe 400 as in FIG. 15A can be positioned within a body orifice orwithin any body passageway, opening, cavity, lumen, vessel, sinus or abody wall, membrane or surface layer of a body structure, such as skin.The method can comprise using the insulative extension member 105 ofFIG. 15A in any wall, membrane or surface layer of a body structureincluding an eye, a brain, a sinus, a nasal passageway, an oral cavity,a blood vessel, an arteriovascular malformation, a heart, an airway, alung, a bronchus, a bronchiole, a larynx, a trachea, a Eustachian tube,a uterus, a vaginal canal, an esophagus, a stomach, a duodenum, anileum, a colon, a rectum, a bladder, a urethra, a ureter, a vasdeferens, a kidney, a gall bladder, a pancreas, a bone, a joint capsule,a tumor, a fibroid, a benign tissue mass, a vascularized tissue mass,hemorrhoid, a tissue mass including a plexus of dilated veins, aneoplastic mass and a cyst. The method can also include positioning ortranslating the extension member 105 for vapor delivery within a bodypassageway, body opening, cavity, lumen, vessel or sinus that cancomprise an airway, an ear canal, a Eustachian tube, a cervical canal, avaginal canal, a nasal sinus, an esophagus, a stomach, a duodenum, anileum, a colon, a rectum, a bladder, a urethra, a ureter, a vasdeferens, a fallopian tube, a blood vessel, a milk duct and a lymphvessel.

The probe 400 of FIG. 15A further includes a handle portion 402configured with on or more other lumens that connect to flow channel 124or one or more channels in the wall of the extension member 105. Forexample, fluid source 420 can be coupled to connector 422 and lumen 423to deliver inflation pressure to a balloon 325 as depicted in FIG. 12C.Still referring to FIG. 15A, another connector 424 and lumen 426 iscoupled, for example to a secondary vapor source 160 as described in thetext accompanying FIG. 2. It should be appreciated that the hub orhandle portion 402 can be configured with from 1 to 10 or more suchconnections to provide various functions.

The probe 400 of FIG. 15A is configured to have vapor source 120directly coupled to fitting 407 to provide a flow of vapor 122 throughthe flow channel 124. It should be appreciated that the probe orassembly 400 of FIG. 15A can be used as an insulative sheath, and anelongated flexible or rigid vapor delivery tool can be introducedthrough the flow channel to deliver vapor to a targeted tissue. Forexample, the probe or assembly 400 could be used as a sheath to extendthrough skin and the wall of a blood vessel, and a vapor deliverycatheter can be introduced through the channel 124 for delivery of vaporfrom a working end of a catheter (not shown).

FIG. 15B illustrates another embodiment of probe 400 with an elongatedextension member 105 for vapor delivery that includes an insulativeregion 320 similar to FIGS. 12D and 15A, which can comprise anconcentric air space 428 with an optional aerogel, or a system ofrecirculation channels. The embodiment of FIG. 15B further includes therecirculation flow channel system and passive valve of FIGS. 14A-14B. Inthe embodiment of FIG. 15B, the flow channel 124 carries the distalvapor flow toward outlet 125 and the second return channel 340 (cf.FIGS. 14A-14B) is concentric about channel 124. It can be seen in FIG.15B that one or more openings 430 allow for vapor flow transition andreverse in direction from flow channel 124 to return channel 340. Inthis embodiment, a solenoid valve 432 in the handle portion 402 isconfigured to close the return channel 430 to thus cause a distal flowof vapor through the outlet 125 as described in the text accompanyingFIGS. 14A-14B. The solenoid 422 is operatively connected to controller150 by electrical connector 412. In the embodiment of FIG. 15B, a fluidsource 420 again is coupled to connector 422 and lumen 423 to deliverinflation pressure to a balloon 325 (not shown) but which is depicted inthe embodiment of FIG. 12C. In FIG. 15B, the connector 424 and lumen340′ is coupled to a negative pressure source 155 which is in turn incommunication with return channel 340 to provide the passive valvefunctionality at the working end to cause vapor flow through the outlet125.

FIG. 15C illustrates an embodiment of probe 400 that has the samefeatures as the embodiment of FIG. 15B except that the extension member105 of FIG. 15C includes an insulative region 320 that comprises aconcentric system of recirculation inflow and outflow channel portions,435 and 435′ respectively, that are coupled through connector 422 to aninflow/outflow source 440 for providing the fluid flows for cooling theextension member wall. The fluid flows provided by the source 440 can beany gas, liquid, cryofluidor the like, and outflow source of system canfurther be configured to apply a partial vacuum while at the same timeas flowing a gas through the channel portions 435 and 435′. While theinflow and outflow channel portions 435 and 435′ are shown asconcentric, such lumens can be axial or helical and extend about thevapor flow channel 124.

FIG. 15D illustrates another embodiment of probe 400 that is similar tothe embodiment of FIG. 15C except that the extension member 105 of FIG.15D is configured with a single concentric flow channel 442 forrecirculation flows that takes the place of two lumens 340 and 435′ inFIG. 15C. It can be seen that flows of vapor 122 will travel distally inflow channel 124 and then through opening 430 to thereafter flowproximally through channel 442 and 442′ in the connector to theatmosphere or negative pressure source 155. In this embodiment, thesource of cooling fluid indicated at 440 provides a flow of air or othergas that flows distally through connector 422 and channel 435 to theworking end 110 and then the cooling gas reverses direction to flowproximally in channel 442 which combines with proximal vapor flows asdescribed above in this paragraph. In this embodiment, the solenoid 432is configured to channel 442 to cause vapor flows to be forced throughoutlet 125 which also thus will interrupt cooling gas flows throughchannel 435. Thus, this system is best suited for treatment methods thatrequire pulsed vapor flows or intermittent vapor flows into a targetedtissue, so that when vapor flows are not directed though outlet 125, thecooling gas will cool the exterior of the extension member 105.

FIGS. 15E-15F illustrate a working end 110 of another embodiment ofprobe 400 similar to that of FIG. 15D except that a slidable sleevemember 450 is utilized as a valve to direct flows distally through theoutlet 125. As can be seen in FIG. 15E, the sleeve 450 is in a proximalposition so that a flow of vapor 122 in channel 124 transitions throughopenings 430 to thereafter flow proximally through channel 442 asdescribed previously. In this embodiment, the reduced cross-sectionoutlet comprises a microporous material indicated at 455 that permitsvapor flow therethrough but prevents flow of water droplets to therebymaintain high vapor quality. The microporous material can be a sinteredmetal filter with pore sizes ranging from about 10 microns to 200microns. Further, in one embodiment illustrated in FIG. 15E, themicroporous material 455 is a resistively heatable material such asnichrome that is coupled to electrical source 460 and controller 150 byopposing polarity electrical leads 462 and 464 to heat the material. Thecontroller 150 can be configured to heat the microporous material 455when the slidable sleeve member 450 is advanced as shown in FIG. 15F. InFIG. 15F, it can be seen that advancing the sleeve member 450 distallyfunctions as a valve to close the openings 430 thus forcing the vaporinto and through the microporous material 455. At the same time, themicroporous material 455 is heated to a temperature capable ofvaporizing any micro-droplets of water in contact with the microporousmaterial 455 and outlets 125 therein to enhance vapor quality.

As can be understood, an aspect of the invention is to provide firstenergy source and heat emitter for converting a liquid media such aswater or saline into a vapor media, for example in a handle 102 of thesystem 100 as shown schematically in FIG. 2. The system can provide asecond energy source and emitter such as microporous material 455 in aworking end of a vapor-carrying tool or extension member to vaporize anywater droplets in a vapor media to thereby provide a high quality vaporwith controlled high energy content, such as a vapor that is at least70%, 80%, or 90% pure water vapor.

One method of the invention for performing a thermotherapy procedurecomprises causing a flow of a gas or liquid within a vapor deliverymember (e.g., extension member 105 of FIGS. 15A-15F) positioned in abody structure, wherein the vapor delivery member is configured toreduce thermal transfer from a high temperature vapor flow to the bodystructure. In one embodiment, the vapor delivery member reduces suchthermal transfer by providing a flow of a gas or liquid in the vapordelivery member to extract heat or evacuating a gas from a channel ofthe member to create or enhance a partial vacuum of the channel. Anothermethod of the invention comprises causing a flow of a gas or liquidwithin a vapor delivery member wherein the flow is provided at aselected pressure provided by a controller 150, and/or wherein thecontroller is responsive to sensing data from a temperature sensor inthe member. The method includes using a thermotherapy probe to provide aflow of vapor through an interior channel of the probe to apply energyto the targeted tissue site. The sleeves can be configured with interiorchannel portions that are axial, co-axial, concentric and/or helical.The interior channel or chamber can form a closed loop or can have atleast one outlet in a surface of the sleeve, for example, to allowleakage of a cooling fluid into an interface with body structure.

FIG. 16 illustrates another embodiment of probe 500 that combinesfeatures of the embodiments of FIG. 12C and 15C with vapor flow channel124 and recirculation channel 340 to provide a passive valve at theoutlet 125. The embodiment further includes a source of cooling fluidindicated at 440 that provides a flow of liquid or gas that flowsdistally through connector 422 and channel 435 to the working end 110and inflates the balloon 315 and then reverses direction to flowproximally in channel 435′ to exit the probe. FIG. 16 illustrates a flowof a fluid into the balloon through port 504 and exiting the balloonthrough port 506 that communicates with outflow channel 435′. Thus, thisembodiment provides a cooling flow through the balloon member 315. Inthe embodiment of FIG. 16, a negative pressure source 155 as in FIG. 12Cis coupled to connector 424 and channel 228 that terminates in at leastone open port 510 in the working end. Thus, the controller 150 canmodulate pressure with a body cavity by controllably extracting mediafrom the cavity such as a uterine cavity (see FIG. 12C).

Remote Vapor Generation Unit And Control Systems

Now turning to FIGS. 17A-18B, several views of a vapor generation systemor source 700 of the invention are shown, which comprises a unit 702that can be connected with a flexible vapor delivery conduit 705 thatextends to a vapor delivery tool or probe (710 or 710′) each having aworking end (715 or 715′). An exemplary instrument or 710 or 710′ can beconfigured for intraluminal or interstitial energy application asdescribed in previous embodiments. For purposes of clarity, interstitialtissue means the tissue that is adjacent to the interspaces of adjoiningtissue while intraluminal tissue is tissue that is adjacent to orsurrounding any lumen. The probe 710 has a working end 715 similar toFIG. 12C with a balloon member 325. The probe 710′ has a working end715′ similar to FIG. 4A but with multiple extendable vapor deliveryneedles 717. The vapor delivery flex-sleeve or conduit 705 can bedisposable or re-useable. The unit 702 includes a canister or generator716 with an interior chamber 718 which has a heat source that appliesenergy to liquid media in the interior chamber to produce a vapor media.Of particular interest, the system 700 is configured to provide a highquality vapor media with precise parameters in terms of vapor quality,exit vapor pressure from the working end 715, exit vapor temperature,and maintenance of the parameters within a tight range over a treatmentinterval. All these parameters must be controlled with a high level ofprecision to achieve controlled dosimetry, no matter whether theparticular treatment calls for very low pressures (e.g., 1-5 psi) over atreatment interval or very high pressures (200 psi or greater) and nomatter whether the treatment interval is in the 1-10 second range or 2to 5 minute range.

In operation, the system 700 relies on developing a selected pressure inthe interior chamber 718 of canister 716 and maintaining the selectedpressure which then can drive the vapor through the working end 715 ofany type of vapor delivery tool or probe and into an interface withtissue without the need for any vapor pumping mechanism. In oneembodiment shown in FIGS. 18A-19, the heat source can comprise first andsecond resistive heating band elements 720 a and 720 b about theexterior of a stainless steel canister 716 capable of withstanding highinternal pressures. An exterior insulator layer about the exterior ofcanister 716 is not shown in FIGS. 18A-18B. The unit 702 includes anumber of features that allow for production of high quality vapor overan extended period of time at the generator outlet 722 (FIG. 17A), theconduit outlet 724 (FIG. 20) or at least one outlet 125 in theinstrument working end 715. In one embodiment, the unit can providevapor media at a selected pressure between 1 psi and 300 psi over anytreatment interval from 1 second to 10 minutes with a variation inpressure of less than 0.1 psi. Stated another way, the system canprovide vapor with less that 10% variability, less than 5% variabilityand less that 2% variability over a treatment interval. By the term highquality vapor, it is meant that the vapor media that is substantially awater vapor that upon a phase change releases at least 300 cal/gm, 350cal/gm, 400 ca/gm, 450 cal/gm or 500 cal/gm. Stated another way, theterm high quality vapor means that a vapor source produces a vapor mediathat is at least 60% pure vapor, at least 70% pure vapor, at least 80%pure vapor, or at least 90% pure vapor on the based or weight or mass.In one embodiment, the system is adapted for providing a therapeuticeffect in a subject and includes an instrument having a working end 715configured for positioning in a subject, a flow channel 802 (FIG. 21)extending through the instrument to at least one outlet in the workingend 715, and a controller 730 and control algorithms operatively coupledto the unit 702 for controlling operational parameters.

Still referring to FIGS. 17A-19, an overview of a method of operatingthe unit 702 is described next, which includes a number of features andaspects of the system that allow the system to provide precisedosimetry. The unit 702 includes a touch screen or panel 732 and powerswitch 734. When the switch 734 is in the ON position, power is appliedfrom electrical source 735 (FIG. 17B) to the controller printed circuitboard (PCB) indicated at 736, the heating circuitry to energize theheater band elements 720 a and 720 b, the pump 740 and other components(see FIGS. 18A-19). In one embodiment, the canister also carries animmersion heater (not visible in FIG. 18A) in the interior chamber 718for allowing raid start up heating of the system. When switch 734 it isin the OFF position, all the power to the unit is turned off. The panelincludes an emergency push button switch 741 that when pressed inward,power for the heating system is turned off. When the switch 741 ispulled outward and the emergency reset switch 742 on the touch screen isactuated, power is delivered to relays 744 and the power for the heatingsystem will be applied if the water level in interior chamber 718 has asufficient water level. If not, the heating circuitry will not beactivated until a water level sensor system 750 determines that asufficient water level has been attained in chamber 718 which thencloses the circuit.

Referring to FIGS. 18A-19, the water level sensor system 750 can haveone or more set points, and in one embodiment is configured with threewater level set points wherein the sensor system includes a float 752 oroptical level sensors in a chamber in fluid communication with theinterior chamber 718 of canister 716. In one embodiment, if the waterlevel is at a first OFF set point, the controller 730 removes powerfrom, or does not permit power application to, the heater band elements720 a and 720 b and the immersion heater. When the water level is at asecond minimum set point, the pump 740 runs until the water levelreaches the third normal set point at which time the pump stops pumping.The heating system can be configured to operate continuously when thewater level is between minimum and the normal set points, subject toother functional algorithms described below. In another embodiment, thelevel sensor system can comprise at least one of a float sensor, anoptical sensor, an electrical sensor and a thermal sensor. Multiplesystems can be provided for redundancy and safety purposes.

In another aspect of the invention, the unit 702 includes a disposablesource of a liquid such as sterile water indicated at 760 in FIGS.17A-17B. The liquid source 760 can be a commercially available flex-wallsac of sterile water, such as a 500 ml, 1000 ml or 2000 ml bag. The bagcan be suspended from any stand or rack to allow a gravity flow of theliquid through connector 762 and inflow channel 764 toward the pump 740.In another embodiment, the liquid container can comprise a plastic sacor bottle particularly adapted for single patient use wherein thecontainer can be disposed of following a single procedure. The system isconfigured with a connector 762 known in the art that allows change outof the liquid source 760 without interruption of use of the system, oralternatively, the purge system (described below) can be actuated uponchanging the liquid source 760. As will be described further below, thesystem also has a disposable liquid collection sac indicated at 765.

In one embodiment, when the unit 702 is first turned on, the controller730 activates a priming subsystem which includes a priming outflowchannel indicated at 766 that flows to collection and cooling reservoirindicated at 780 in FIGS. 18A-19. In operation, the prime solenoid 784(FIG. 19) is activated for a short period of time during initialactivation of pump 740, for example for 1 to 60 seconds. This primingstep provides that air in the outflow from pump 740 is directed throughthe prime outflow channel 766 in order to prime and relieve the pump,which thus reduces the possibility of unwanted air entering the interiorvaporization chamber 718 of canister 716. This priming circuit can beactivated when the touch screen button for “prime” is pressed or when anion sensor 785 described below detects a liquid media havingunacceptable quality. In the case of the unacceptable liquid quality,the controller re-directs the liquid into and through the primingoutflow channel 766 of the priming subsystem.

In another aspect of operation, the unit 702 has an output circuit withoutput flow channel 790 which includes an output or delivery solenoid792 which can be actuated by either a switch on the touch screen, or aninstrument actuation switch such as a handswitch or footswitch. In orderto actuate the output solenoid 792, the controller 730 includes analgorithm that requires that chamber 718 of vapor canister 716 reach anoperating pressure set point and also can require that a flow channel800 in the conduit 705 (FIG. 19) or a flow channel 802 in instrument 710reach an operating temperature set point. The operating pressure setpoint can be any pressure between 1 psi and 500 psi, and in variousprocedures, optimal pressure or driving pressure has been found to be aslow at 5 psi and as high as 250 psi. In one embodiment, a purgesubsystem and controller algorithm is provided wherein the purgesolenoid 804 is activated when treatment has been initiated and theoutput solenoid 792 has also been activated. This can be a very shortperiod of time for the valve to be open, for example from 0.1 second to5 seconds, resulting in a high velocity purge to remove any residuecondensate in the flow channel 800 of the conduit 705 or flow channel802 of the instrument. The purge subsystem can be activated by theswitch on the touch screen 732.

As described above, the unit 702 has a collection and cooling reservoir780 that is configured to receive remainder liquid media from systemoperation, which can include liquid from the prime system, from thepurge system, from a conduit sterilization system, from the bypasssystem, and from extracted liquid from the working end 715 of aninstrument. The cooling system includes a heat exchanger and fans as isknown in the art to cool the liquid and upon sensing a cooledtemperature with a temperature sensor. The controller 730 is configuredto open a discharge or drain solenoid 812 to discharge the remainderliquid into the collection sac 765 (see FIGS. 17A-19).

In one embodiment, the unit 702 includes a liquid quality detectionmeans for detecting water quality from source 760 which can be an ionsensor indicated at 785 in FIG. 18A. The ion sensor comprises spacedapart electrodes that sense a parameter of the liquid inflow such asimpedance and/or capacitance which is determinative of sterile water. Ifthe sensor detects impure water, the controller 730 can further includean algorithm to run a prime cycle when a new liquid source 760 isconnected to the unit 702 to purge any impure water from the systemthrough the priming outflow channel 766. As described above, thisremainder liquid is then directed to the collection and coolingreservoir 780. A method of the invention utilizes the sensor system toprovide a read-out of an ion level in the liquid media, and can includean algorithm that disables the system with a system lock-out thatrequires a new liquid source to be connected to the system to overcomethe lock-out.

In another embodiment, the system includes a stability subsystem andcircuit, wherein stability solenoids 814 and 816 can be used to actuatea heating system in flow channel 800 in the conduit 705 and optionallythe flow channel 802 in instrument 710 (FIG. 19). This system and methodreduces condensation in the output channels 790 to ensure more accurateand consistent treatment dosimetry, particularly at lower treatmentdurations. This system also helps maintain sterilization of the deliverytube during the idle phases of the system. The solenoids 814 and 816also can be energized by a switch on the touch screen 732 and can becontrolled to the temperature set point which is programmed into thecontroller 730. In one embodiment, the stability subsystem includesmultiple temperature sensors, both at an interior of the flow channel800 and at an outer layer of the structure surrounding the flow channel(see FIG. 20) to thereby determine the heat capacity of the structureand losses that may occur in the flow channel 800.

In another aspect of the invention, the unit 702 provides for a hotdrain subsystem (FIG. 19). The drain or discharge solenoid 812 isactivated by switch on the touch screen 732 at the temperature set pointand the pressure set point. This subsystem can use the vapor pressurestored in the tank to drive remainder liquid out the lower portionchamber 718 of canister 716. In operation, the hot drain subsystem isused to remove liquid from the unit after use when the system is to beshut down for any period of time. In use, the hot drain subsystem causesthe liquid to flow to the cooling reservoir 780 for cooling as describedpreviously.

In another embodiment, the system provides a cold drain subsystem (FIG.19). In this embodiment, the cold drain solenoid 818 is activated by aswitch on the touch screen 732 which is enabled when pressure in thecanister is low, for example between 0 and 1 psi. In a cold shut-down,solenoid 820 and an associated air pump 822 is configured to provideabout 1 psi air through a 0.2 micron air filter 824 to the interiorchamber 718 of the canister wherein the sterile air pushes out liquid tothe collection reservoir and cooling system 780. A cold shut-down can berequired for example when there is a power outage. In one embodiment,the air pump system 722 includes a battery back-up.

In general, one embodiment of the invention comprises a medical systemfor providing a therapeutic effect in a subject that includes aninstrument having a working end configured for positioning in a subject,and a flow channel extending through the instrument to an outlet in theworking end, a vapor source capable of providing a vapor flow at theoutlet, and a controller operatively coupled to the vapor source forcontrolling operational parameters wherein the vapor source is capableof providing at least 60% water vapor, at least 70% water vapor, atleast 80% water vapor or at least 90% water vapor.

As described above, in one embodiment, the system 700 is configured witha number of subsystems that allow for the production of high qualityvapor. Thus, the controller 730 includes algorithms for controlling thesystem's operations, which include: (i) algorithms that control atreatment cycle for delivering vapor media to the instrument and tissue;(ii) algorithms that which control a modulation cycle for modulatingvapor media parameters in response to feedback signals of pressure,temperature, and/or vapor flow rates; (iii) algorithms that whichcontrol a pump cycle for pumping a liquid media into the vapor source;(iv) algorithms that which control a sensing cycle for determiningsterility of liquid media prior to introduction; (v) algorithms thatcontrol a rejection cycle for rejecting liquid media prior tointroduction to the vapor source; (vi) algorithms that control a primingcycle for priming the pump to prevent air flow to the vapor source;(vii) algorithms that control a purge cycle for eliminating condensationin system channel portions and for maintaining system readiness betweenmultiple uses; (viii) algorithms that control a liquid level controlcycle for maintaining a liquid volume in the vaporization source; (ix)algorithms that control a cooling cycle for cooling remainder liquidmedia; (x) algorithms that control a collecting cycle for collectingremainder liquid media; (xi) algorithms that control a check cycle forchecking the system for leakage; (xii) algorithms that control astabilization cycle for evaluating stability of the vapor quality;(xiii) algorithms that control a sterilization cycle for sterilizing aconduit for coupling the vapor source to an instrument; (xiv) algorithmsthat control a shut-down cycle for hot shut-down of the vapor source;(xv) algorithms that control a cold shut-down of the vapor source; (xvi)algorithms that control an emergency shut down cycle; (xvii) algorithmsthat control a sterilization cycle for sterilizing the interior chambersand channels of the system; and (xviii) algorithms that control a dryingcycle for drying the vapor source with sterile air.

Other system embodiments include controller algorithm adapted for othersystem functionality that may not be directly related to vapor qualitybut nevertheless are directly related to dosimetry and treatmentintervals, such as: (i) algorithms that control an imaging cycle foractuating an imaging system; (ii) algorithms that control a modulationcycle for modulating vapor media parameters in response to imaging;(iii) algorithms that control an injection cycle for injecting apharmacological agent through the instrument; (iv) algorithms thatcontrol an injection cycle for injecting gas to alter mass average vaportemperature; (v) algorithms that control an aspiration cycle foraspirating media through the instrument, (vi) algorithms that control anactuation cycle for actuating a working end component; (vii) algorithmsthat control an actuation cycle for actuating at least one heatingsystem in a flow channel in a working end, and (viii) algorithms thatcontrol vapor media flow between multiple working end components forcontrolling the geometry of treated tissue.

In one embodiment referring to FIG. 20, a medical system as describedabove includes a sterilizable vapor delivery flex-tube or conduit 705with an interior conduit flow channel 800 configured to receive thevapor media from a vapor source and transport the vapor media toinstrument 710 with working end 715 configured for positioning at atargeted site in a subject. The vapor source unit 702 includes connector825 (FIG. 17A) that is configured for detachable connection to proximalquick-lock connector 826 on conduit 705 which in one embodiment is keyedwith elements 828 to connect at least first and second flow channels(not shown) in unit 702 to a cooperating vapor flow channel 800 in theconduit 705 and at least one other flow channel. The distal end of theconduit 830 has a distal quick-lock detachable connector 835 that isconfigured for connection to cooperating connector 836 on an instrumentor probe 710 (FIG. 17A) having a vapor flow channel 802 therein. In oneembodiment, the conduit flow channel 800 is configured for a looped flowfrom flow channel 800 to return channel 838, which is similar to thesystem of FIGS. 14A-14B to provide a sterilization circuit. Inoperation, this looped flow functions as a passive valve as indicated inFIGS. 19-20. The conduit 705 includes a distal outlet flow channel 840which delivers vapor to the vapor channel 802 in instrument 710. Thelooped flow can be accomplished with either concentric or laterallyspaced apart channels. As can be seen in FIGS. 19-20, the return flowchannel 838 of the conduit couples with a return channel 842 (FIG. 19)in the unit 702 that leads to the cooling and remainder liquidcollection reservoir 780. In another embodiment, the looped flow portioncan be detachable (not shown) from the conduit 705 and can bedisposable, wherein the conduit could then be sterilizable by vapor flowthough the inflow and outflow channels for a requisite time. Similarly,the looped flow portion or a similar detachable member can be fitted tooutlet fitting 825 on unit 702 to allow sterilization of the flowchannels in the interior of the unit 702.

In one aspect of operation relating to the cooling and collectionreservoir 780, a method for providing a therapeutic effect comprisespositioning a working end of an instrument at a targeted site in asubject, actuating a vapor generator to convert a flow of liquid mediainto a flow of vapor media, introducing the flow of vapor media througha flow channel in the instrument to an outlet in the working end therebyapplying energy to the targeted site, and collecting remainder liquidmedia in a disposable container in fluid communication with the vaporgenerator and/or the instrument. The can include cooling the remainderliquid media prior to the collecting step. The method includes utilizinga controller 730 and control algorithm for controllably cooling theremainder liquid media and opening a valve to allow collection of theremainder liquid. The method includes cooling the remainder liquid mediato less than 80° C., 70° C., 60° C. or 50° C. Further, the method caninclude condensing remainder vapor media into liquid media prior to thecollecting step, collecting excess liquid media from the vaporgenerator, collecting liquid media following a sterilization cycle,collecting liquid media following a vapor generator shut-down. Further,the method can provide first and second control algorithms forcontrollably collecting cooled remainder liquid or heated remainderliquid, respectively.

In one embodiment, the medical system provides cooling and collectionsubsystem that includes a disposable container 765 in communication thevapor generator and/or instrument for receiving remainder liquid media,wherein the container has a wall that is transparent or translucent andis capable of withstanding liquid media temperatures of 70° C., 80° C.,90° C. or 100° C. The disposable container 765 can have a capacity of atleast 250 ml, 500 ml or 1000 ml. In one embodiment, the disposablecontainer 765 has wall or wall portion including a thermochromicmaterial 848 for indicating a temperature of the contents (FIG. 17A).

In another aspect of the invention, the medical system as describedabove provides a vapor media outflow channel 790 from the chamber 718wherein the channel can have a portions of the flow channel in the unit702, the conduit 705 and the instrument 710. Referring to FIG. 21, across section of a flow channel 800 and surrounding structure or wall850 is shown in a component indicated at 852 which may be conduit 705 orany other part of the system. In one embodiment, the structure includesa thin inner layer 854 around the flow channel which is of abiocompatible fluid impermeable material such as a polymer (Teflon®) ora metal such as stainless steel. Flexible sleeves can include anelectroless plating over a polymer base to provide layer 854. Outwardfrom the inner layer 854 is an insulating layer 855 that can comprise asilica aerogel, hollow glass microspheres, air channels or voids havinga partial vacuum, or any other insulation materials known in the art.The exterior 858 of the wall 850 can be any suitable layer, and caninclude a Nomex material. In one embodiment, the insulative layer 855,or the inner layer 854 and insulting layer 855, or the entire wall 850,as described above, can have a thermal conductivity of less than 0.05W/mK, less than 0.01 W/mK or less than 0.005 W/mK. In another aspect ofthe invention, the wall is configured with a material around the channelhaving a heat capacity of less than 2000 J/kgK. In one embodiment, thereare no fittings, surfaces or materials interfacing the flow channel 800that have a substantial heat capacity, thus preventing condensation.Alternatively, fittings and surfaces can be fitted with a heatingelement.

In another aspect of the invention, the medical system has a probeand/or conduit having a flow channel 800 extending therethrough from afirst end to an open second open, wherein a wall of the flow channel isconfigured to limit energy losses in a water vapor flow between thefirst end and the second end to less than 500 cal/gm. In anotherembodiment, the wall is configured to limit the energy losses to lessthan 250 cal/gm, less than 200 cal/gm, less than 150 cal/gm, less than100 cal/gm or less than 50 cal/gm.

In another aspect of the invention, the medical system includes a probeand/or conduit having a flow channel extending therethrough from a firstend to an open second open, wherein the wall of the flow channelconfigured with at least one heating element 860 (FIG. 21) to limitenergy losses in a vapor flow between the first end and the second end.In one embodiment, the wall is configured with at least one resistivecoil heater, an inductive coil for heating a wall layer such as amagnetic-responsive electroless plating, a conductive and resistivepolymer coupled to an electrical source, or a polymer having a positivetemperature coefficient of resistance coupled to an electrical source.The probe member can be rigid or flexible.

In another aspect of the invention, the medical system provides a vaporsource, a flow channel having a first end in communication with thevapor source and a second open end in an instrument working end, andstructure surrounding at least an intermediate portion of the flowchannel between the first end and the second end that is configured tolimit energy losses in a vapor flow to less than 50%, 40%, 30%, 20% or10%. The length of the flow channel can greater than 50 mm, 100 mm, 200mm or 500 mm. In another aspect, the structure surrounding at least anintermediate portion of the flow channel between the first end and thesecond end comprises a first surface layer and a second subsurface layerhaving a substantially low heat capacity. For example, the heat capacityis less than 2000 J/kgK. In one embodiment, an interior layer of thewall comprises an aerogel.

In a method of use, the system can be used to treat a targeted sitesthat is interstitial, topical or within at least one of a body space,passageway, lumen, cavity, duct, vessel or potential space. A method ofthe invention for to treating a targeted sites that can be interstitial,intraluminal or topical includes providing a vapor source consisting ofa pump configured for providing a flow of liquid media from a liquidmedia source into a vaporization chamber having a heating mechanism,actuating the pump to direct a liquid media flow through an inflowchannel between the liquid source and the pump, and applying energy fromthe heating mechanism to convert a substantially water liquid media intovapor media and controllably introducing said vapor into an interfacewith tissue to cause the intended effect, wherein the vapor media is atleast 60% water vapor, at least 70% water vapor, 80% water vapor or atleast 90% water vapor. The method includes applying energy with media inwhich the percentage of water vapor varies of less than 10% over 5minutes, 10 minutes, 30 minutes, 60 minutes and 120 minutes. The abilityof the system to produce vapor without variation is critical for acontrolled dosimetry, which is needed for both interstitial treatments,and treatments of a body lumen, cavity, passageway, vessel, conduit,space or potential space. In another method, the system can be used totreat bone, for example to ablate tumors in a bone, to ablate bonemarrow, or to cause surface coagulation and sealing of a bone.

In another method of the invention, a pharmacological agent can beintroduced into a targeted site prior to the controlled introductionsaid vapor to the site. In one example, an anti-inflammatory agent canbe introduced through the vapor probe prior to vapor delivery, such asin a lung or airway treatment, a prostate treatment, a uterinetreatment, a fibroid treatment, an endovascular treatment or in anytumor ablation. The method also can introduce the pharmacological agentinto a targeted site mixed with vapor media. The pharmacological agentcan be an anti-inflammatory agent, an antibiotic or an anesthetic agent.

In another method of the invention, the medical system includes acontroller configured to control an operational parameter, which caninclude liquid media flow rate into the interior chamber 718 forconversion to vapor, the liquid media pressure, the liquid mediatemperature, the vapor media flow rate which is created by thevaporization parameters, the vapor quality as described above, the vaporpressure in the working end and the vapor temperature at the workingend. In one embodiment, the system can have multiple heating systems,for example in FIGS. 18A, 18B, 19 and 22, the interior chamber 718 canbe configured with a first immersion heating system 865 and a secondheating system comprising lower band heating element 720 a which allowfor rapid start-up of the system to operational parameters, for examplein less than 5 minutes, less than 4 minutes, less than 3 minutes or lessthan 2 minutes. As can be seen in FIG. 22, the interior chamber 718 ofcanister 716 has a first lower chamber portion 868 and second upperchamber portion 868′ which are separated by any suitable configurationof member or baffle 870 with an open region between the lower and upperchamber portions to allow upward vapor flow and downward condensationflow, and can be at least one central opening indicated at 872. In oneembodiment, the upper chamber portion 868′ is configured with a thirdheating system or band heater 720 b to maintain vapor in the upperchamber as the vapor exits through outlet 880 into delivery tube 790. Inoperation, the baffle 870 functions as a splash guard to prevent boilingliquid from splashing into the upper chamber while the at least oneopening 872 cooperates with a sloped surface 874 of the baffle to allowany condensation to drip back into the lower chamber 868. As can be seenin the schematic drawing of FIG. 22 and FIG. 21, the conduit 705 can beconfigured with a fourth heating system 860, and the flow channel in aninstrument 710 can be configured with a similar or fifth heating system(see FIG. 21), all functioning in accordance with controller 730 tomaintain or enhance vapor quality as the vapor flows from the chamber718 to an outlet 725 in working end 715. In one embodiment, the interiorchamber 718 includes a piezoelectric pressure sensor (not shown) coupledto the controller 730.

In another method of the invention, the system operator uses an imagingsystem to acquire images or other data concerning a site targeted forenergy delivery to thereby derive at least one selected site treatmentparameter, and from this data determines energy dosimetry. Followingthis determination, the vapor media is introduced into the site whereinthe vapor media is configured to undergo a phase change to thereby applya predetermined energy dose to the site to provide an intended effect.The derived site parameter can be volume of tissue of the targeted site,for example in a prostate treatment. Alternatively, the derived siteparameter can be surface area or cavity volume of the targeted site, forexample in a global endometrial ablation treatment. The derived siteparameter can be volume or weight of tissue of the targeted site, forexample in a prostate treatment, lung treatment, or tumor treatment. Inother related methods, the site parameter can be at least one of theheat capacity of tissue of the targeted site, the thermal diffusioncharacteristics of tissue of the targeted site, the heat sinkcharacteristics of tissue of the targeted site, the fluid content ormobility within a targeted body structure, the volume of any cavity ofany targeted organ, the cross section of a lumen of a vessel, thehydration of tissue of the targeted site, the geometry of the targetedsite, or the blood flow within the targeted site. The targeted site thatcan be images can be any of the following: a sinus, a nasal passageway,an oral cavity, a blood vessel, an arteriovascular malformation, aheart, an airway, a lung, a bronchus, a bronchiole, a collateralventilation pathway in a lung, a larynx, a trachea, a Eustachian tube, auterus, a vaginal canal, a cervical canal, a fallopian tube, anesophagus, a stomach, a duodenum, an ileum, a colon, a rectum, abladder, a urethra, a ureter, a vas deferens, a kidney, a gall bladder,a pancreas, a bone, a joint capsule, a tumor, a fibroid, a neoplasticmass, brain tissue, skin, adipose tissue, an ovary, a cyst, a retina, apotential space between body structures and a lower vapor-permeableregion adjacent a higher vapor-permeable region.

In the method described above, the imaging step can be accomplished byat least one of ultrasound, x-ray, Mill, PET and CAT scan, or thermalimaging system. The resulting dose can be applied over an interval of atleast 0.1 second, 1 second, 5 seconds, 10 seconds, 30 seconds, 60seconds, 120 seconds and 240 seconds. The method and dose can applyenergy in the range of from 0.1 Watt to 1000 Watts. The method ofdetermining dosimetry can be performed independent of the applyingenergy step. In another method, the determining dosimetry step can beperformed contemporaneous with the applying energy step. Also, themethod can include contemporaneous determination of dosimetry with theimaging step which provides feedback to adjust dosimetry. In one method,vapor is introduced into a targeted site in the subject wherein thevapor media is configured to undergo a phase change thereby applyingenergy to provide an intended effect, the targeted site is imagedcontemporaneous with applying energy, and the dose of applied energy ismodulated in response to data obtained from the imaging step. Themodulating step can include controlling the interval of applying energy,controlling the temperature of the vapor media, controlling the pressureof the vapor media and controlling the quality of the vapor media.

In one method, the a heat applicator is introduced into a targeted sitein the subject, and the targeted site is imaged with a microbolometercarried at a working end of the heat applicator at least one of priorto, contemporaneous with, or after applying energy and optionallymodulating the dose of applied energy in response to data obtained fromthe microbolometer imaging step. The modulating step can be based on acontroller and algorithm, or based on an operator's visual assessment.The modulating step can be configured to apply energy to maintain anaverage temperature, or to not exceed a peak temperature, can comparepre-treatment temperature to intraoperative temperature. The method canutilize the microbolometer to produce an intraoperative thermogram stillimage or video images of a body structure to thereafter link to thecontroller for modulating energy application. Thus, a device of theinvention comprises an instrument having a working end with a heatapplicator and a microbolometer chip carried by the working end.Further, the working end is configured for positioning in a subject, andhas a flow channel extending through the instrument to an outlet in theworking end, and the heating mechanism is capable of converting a liquidmedia into a vapor media in an interior chamber of the system forintroduction into the flow channel.

Although particular embodiments of the present invention have beendescribed above in detail, it will be understood that this descriptionis merely for purposes of illustration and the above description of theinvention is not exhaustive. Specific features of the invention areshown in some drawings and not in others, and this is for convenienceonly and any feature may be combined with another in accordance with theinvention. A number of variations and alternatives will be apparent toone having ordinary skills in the art. Such alternatives and variationsare intended to be included within the scope of the claims. Particularfeatures that are presented in dependent claims can be combined and fallwithin the scope of the invention. The invention also encompassesembodiments as if dependent claims were alternatively written in amultiple dependent claim format with reference to other independentclaims.

1. (canceled)
 2. A method of ablating an endometrium of a uterus, themethod comprising: inserting a probe working end through a cervix intothe uterus, the probe comprising a delivery lumen, an exit port, and aballoon disposed proximal to the exit port; expanding the balloon suchthat the balloon prevents retrograde flow from the uterus; afterexpanding the balloon: delivering a pharmacological agent to the uterus;delivering vapor media from a vapor source to the uterus whilecontrolling a pressure within the uterus; and condensing the vapor mediato thereby release heat of vaporization to ablate at least portions ofthe endometrium.
 3. The method of claim 2, wherein delivering thepharmacological agent to the uterus comprises delivering thepharmacological agent from a pharmacological agent source through thedelivery lumen.
 4. The method of claim 2, wherein the pharmacologicalagent is delivered to the uterus before delivering the vapor media tothe uterus.
 5. The method of claim 2, wherein the pharmacological agentand the vapor media are delivered to the uterus simultaneously.
 6. Themethod of claim 5, wherein the pharmacological agent is mixed with thevapor media.
 7. The method of claim 2, wherein pharmacological agentcomprises an anti-inflammatory agent, an antibiotic, or an anestheticagent.
 8. The method of claim 2, wherein controlling the pressure withinthe uterus comprises maintaining the pressure in the uterus between 0.1psi and 50 psi.
 9. The method of claim 2, wherein controlling thepressure within the uterus comprises maintaining the pressure in theuterus between 0.2 psi and 10 psi.
 10. The method of claim 2, whereincontrolling the pressure within the uterus comprises maintaining thepressure in the uterus between 0.5 psi and 5 psi.
 11. The method ofclaim 2 wherein the vapor media comprises water vapor.
 12. The method ofclaim 2 wherein delivering vapor media from the vapor source to theuterus comprises delivering the vapor media at a flow rate in a range of0.001 ml/min to 20 ml/min.
 13. The method of claim 2 wherein deliveringvapor media from the vapor source to the uterus comprises delivering thevapor media at an inflow pressure in a range of 0.5 psi to 1000 psi. 14.The method of claim 2 wherein delivering vapor media from the vaporsource to the uterus comprises delivering the vapor media for aninterval in a range of 0.1 seconds to 600 seconds.
 15. The method ofclaim 2, wherein controlling the pressure within the uterus comprisesmaintaining the pressure in the uterus between 0.1 psi and 2 psi. (New)The method of claim 2, further comprising controlling a vapor quality ofthe vapor media delivered to the uterus.
 17. The method of claim 16,wherein controlling the vapor quality of the vapor media delivered tothe uterus comprises controlling an application of energy generated byan energy source.
 18. The method of claim 17, wherein the energy sourceis a radiofrequency energy source.
 19. The method of claim 16, whereincontrolling the vapor quality of the vapor media delivered to the uteruscomprises generating vapor media that releases at least 300 cal/gm uponphase change of the vapor media.
 20. The method of claim 16, whereincontrolling the vapor quality of the vapor media delivered to the uteruscomprises controlling a percentage of the vapor media that is purevapor.
 21. The method of claim 16, wherein controlling the vapor qualityof the vapor media delivered to the uterus comprises flowing the vapormedia through a microporous material proximate the vapor exit port.